I almost always try to explicitly set the cursor and lock types before opening a recordset.
And here's a related, interesting link:
Cursor & LockType Performance Issues - 6/27/1999
Cursor & LockType Performance Report - 6/27/1999
Test was done for inserting recs instead of just getting them.
Use adOpenForwardOnly cursor type (the default) whenever possible for speed, but use adOpenStatic if want to use objRS.MovePrev or objRS.RecordCount.
Use adLockReadOnly lock type (the default) whenever possible for speed, but use adLockOptimistic when updating and deleting or adLockPessimistic if leaving a recordset open for editing which of course one shouldn't do on the Web anyway.